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1.
Sci Total Environ ; 752: 142062, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207489

RESUMO

We reviewed over 226 studies dealing with arsenic (As) in water bodies (124 sites or regions; 5,834 samples), soils (44; 2,700), sediments (56; 765), rocks (6; 85), mine waste (25; 582), continental plants (17 (77 species); 571), continental animals (10 (32 species); 3,525) and aquatic organisms (27 (100 species) 2,417) in Mexico. In general, higher As concentrations were associated with specific regions in the states of Hidalgo (21 sites), San Luis Potosi (SLP) (19), Baja California Sur (15), Zacatecas (5), and Morelos (4). High As levels have been detected in drinking water in certain locations of Coahuila (up to 435 µg L-1) and Sonora (up to 1004 µg L-1); in continental surficial water in Puebla (up to 780 µg L-1) and Matehuala, SLP (up to 8684 µg L-1); in groundwater in SLP (up to 16,000 µg L-1) and Morelia, Michoacán (up to 1506,000 µg L-1); in soils in Matehuala, SLP (up to 27,945 µg g-1) and the Xichú mining area, Guanajuato (up to 62,302 µg g-1); and in sediments in Zimapán, Hidalgo (up to 11,810 µg g-1) and Matehuala, SLP (up to 28,600 µg g-1). In contaminated arid and semi-arid areas, the plants P. laevigata and A. farnesiana exhibit the highest As levels. These findings emphasize the human and environmental risks associated with the presence of As in such regions. A synthesis of the available techniques for the removal of As in water and the remediation technologies for As contaminated soils and sediments is given. The As occurrence, origin (geogenic, thermal, mining and anthropogenic) and evolution in specific regions is summarized. Also, the mobilization and mechanisms to explain the As variability in continental environments are concisely given. For future research, a stratified regional sampling is proposed which prioritizes critical sites for waters, soils and sediments, and biota, considering the subpopulation of foods from agriculture, livestock, and seafood. It is concluded that more detailed and comprehensive studies concerning pollution levels, as well as As trends, transfer, speciation, and toxic effects are still required.


Assuntos
Arsênico , Poluentes Químicos da Água , Animais , Arsênico/análise , Biota , Monitoramento Ambiental , Humanos , México , Solo , Poluentes Químicos da Água/análise
2.
Sci Total Environ ; 753: 141871, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32891997

RESUMO

Arsenic is a global pollutant that can accumulate in rice and has been confirmed to disturb the gut microbiome. By contrast, the influence on the gut mycobiome is seldom concerned because fungi comprise a numerically small proportion of the whole gut microcommunity. To expand the detection of the mycobiome in different gut sections of mammals and investigate the influence of food arsenic on the gut mycobiome in the digestive tract, we treated mice with feeds containing different compositions of arsenic species (7.3% sodium arsenate, 72.7% sodium arsenite, 1.0% sodium monomethylarsonate, and 19.0% sodium dimethylarsinate) in rice at a total arsenic dose of 30 mg/kg. After 60 days of exposure, the feces of four different sites, the ileum, cecum, colon, and excreted feces, were collected and analyzed by internal transcribed spacer gene sequencing. Among the samples, the major fungal phyla were Ascomycota, Basidiomycota, and Zygomycota; the top 10 fungal genera were Aspergillus, Verticillium, Penicillium, Cladosporium, Alternaria, Fusarium, Ophiocordyceps, Trametes, Mucor, and Nigrospora. In control mice, along the murine digestive tract, the mycobial richness and composition were significantly changed; Aspergillus and Penicillium possessed the higher ability to be stabilized in the murine gut, and larger proportions of positive correlations were observed among the major fungi. After arsenic exposure, the fungal composition was more disturbed in the intestinal tract than in feces. Along the digestive tract, arsenic can trigger larger mycobial variations, and the sensitivities of major fungi to arsenic were changed. Thus, the murine intestinal spatial mycobiota are more perturbed than excreted fecal mycobiota after food arsenic exposure. Feces are insufficient to be selected as a representative of the gut mycobiota in arsenic exposure studies.


Assuntos
Arsênico , Micobioma , Animais , Fezes , Fungos , Intestinos , Camundongos , Trametes
3.
Sci Total Environ ; 750: 142209, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182188

RESUMO

While the impacts of arsenic (As) and Magnaporthe oryzae on rice have been well-studied, a dearth of knowledge exists on how rice responds to their combined stress. Moreover, increasing exogenous silicon (Si) can alleviate M. oryzae infection and As uptake, but how increasing exogenous Si affects the combined stress of M. oryzae and As is unknown. We grew three cultivars of rice that varied in their susceptibility to As and M. oryzae under low (50 µM, SiL) and high (1500 µM, SiH) Si with and without As (4 µM, 80/20 As (III)/As(V)) and with or without M. oryzae infection and examined the impacts of treatments on plant As and Si concentrations, severity of disease by M. oryzae, and stress via targeted gene expression. SiH treatments generally decreased shoot As concentrations by 20-70% compared to SiL treatments depending on cultivar and M. oryzae exposure. There was no effect of Si or As treatments on percent of leaf diseased in the As-tolerant cultivar M206, but in the As-sensitive cultivar IR66, SiH treatment decreased percent of leaf diseased in the absence of As and had no impact when As was present. In the M. oryzae-susceptible Sariceltik, plants receiving SiH had significantly fewer lesions than those receiving SiL and plants with the fewest lesions were in the SiH + As treatments. Plants that were exposed to As + M. oryzae were the most stressed when grown under SiL, but this stress response was lowered by SiH treatments. A separate pathogenicity assay with Sariceltik showed that in contrast to our hypothesis, As exposure decreased lesion growth, particularly under SiH treatments, and lessened the impact of M. oryzae on rice. These results suggest that rice grown under replete Si will be able to withstand combined stressors of M. oryzae and As, but will be highly stressed under Si deficient scenarios.


Assuntos
Arsênico , Magnaporthe , Oryza , Arsênico/toxicidade , Doenças das Plantas , Silício/toxicidade
4.
Sci Total Environ ; 750: 141517, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829259

RESUMO

Blood arsenic has various toxicities including carcinogenicity, but urinary concentrations are often substituted to determine the exposure level. Since there is little information on the relation of urinary arsenic species to blood arsenic, the aim was to investigate relationships between blood total arsenic (T-As) and the urinary species adjusted by creatinine and specific gravity (SG). Blood and spot urine samples were collected from 109 Japanese subjects aged 18-66 years without occupational exposure. Positive correlations of blood T-As (median, 3.49 µg/L) with urinary creatinine-adjusted and SG-adjusted T-As and arsenobetaine were statistically significant and greater than those with the unadjusted ones. The magnitude of associations of blood T-As with creatinine-adjusted arsenic species was significantly larger than those with unadjusted or SG-adjusted ones. Most of the correlation coefficients among urinary arsenic species concentrations were significant in three adjustment methods, but there was not a significant correlation between monomethylarsonic acid and arsenobetaine after urinary creatinine and SG corrections. Given multiple regression analysis, plasma T-As concentrations showed significant relations to creatinine-adjusted T-As, dimethylarsinic acid, and arsenobetaine concentrations, but erythrocyte T-As did hardly reflect the variation of urinary arsenic species. In conclusion, creatinine-adjusted arsenic concentrations are suggested to be the most appropriate predictor of blood T-As; by contrast, use of the urinary unadjusted arsenic concentration may result in a misleading interpretation of inorganic arsenic toxicity because the associations between inorganic and organic arsenic species based on the unadjusted concentration were mutually close. Plasma T-As appeared to be the best indicator of low-level exposure in blood samples.


Assuntos
Arsênico , Exposição Ocupacional , Adolescente , Adulto , Idoso , Ácido Cacodílico , Exposição Ambiental , Humanos , Pessoa de Meia-Idade , Urinálise , Adulto Jovem
5.
Sci Total Environ ; 750: 141547, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858293

RESUMO

High total urinary arsenic concentrations and low estimated glomerular filtration rate (eGFR) increase the risk of renal cell carcinoma (RCC). This study aimed to determine whether other metals or metalloids can affect RCC. A total of 401 patients with RCC and 774 age- and sex-matched controls were recruited between November 2006 and December 2012 in Taiwan. Surgical resection or image-guided biopsy of renal tumors was performed to pathologically verify RCC. High-performance liquid chromatography linked to a hydride generator and atomic absorption spectrometer were used to measure the urinary arsenic species concentrations. Inductively coupled plasma mass spectrometry was used to determine plasma selenium and red blood cell cadmium and lead concentration. Plasma selenium levels were inversely related to RCC, whereas red blood cell cadmium levels were directly related to RCC. The odds ratio (OR) and 95% confidence interval (CI) were 0.14 (95% CI, 0.10-0.20) and 1.33 (95% CI, 1.03-1.72), respectively. A low plasma selenium level tended to interact with high total urinary arsenic levels or with high red blood cell cadmium concentration to increase the OR of RCC. In particular, low eGFR multiplicatively interacted with high red blood cell cadmium concentration to increase the OR of RCC (Pinteraction=0.003). This study was the first to find a significant multiplicative interaction between eGFR and the red blood cell cadmium levels on the increased OR of RCC.


Assuntos
Arsênico , Carcinoma de Células Renais , Neoplasias Renais , Selênio , Cádmio , Estudos de Casos e Controles , Receptores ErbB , Eritrócitos , Taxa de Filtração Glomerular , Humanos , Taiwan/epidemiologia
6.
Sci Total Environ ; 750: 141672, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32862003

RESUMO

Contaminations by heavy metals in the environment always exist as a mixture of both metal and metalloid. Thus, it is a challenge to simultaneously remove both components due to their adverse chemical behaviors. Herein, effective cadmium (Cd) and arsenic (As) removal in aqueous solution was achieved by use of a novel composite, which was synthesized by Bacillus sp. K1 loaded onto Fe3O4 biochar (MBB). The combination with Bacillus sp. K1 provided new biosorption sites such as amine and hydroxyl groups in the composite surface, which significantly increasing the removal capability of Cd(II) by 230% when compared with the raw magnetic biochar. Both competition and synergy effects were found in binary system. Adsorption of As(III) extended active sites for capturing Cd(II), which appeared on the surface of the MBB as type B ternary surface complexes. The maximum adsorption capacity of Cd(II) and As(III) reached 25.04 and 4.58 mg g-1 in a binary system, respectively. In summary, this environmentally friendly composite is promising for simultaneous Cd(II) and As(III) remediation.


Assuntos
Arsênico , Poluentes Químicos da Água , Adsorção , Cádmio/análise , Carvão Vegetal , Fenômenos Magnéticos , Poluentes Químicos da Água/análise
7.
Sci Total Environ ; 751: 141623, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32877793

RESUMO

There is a growing interest in the use of adsorbent nanoparticles to mitigate the toxic effects of pollutants in natural matrices. However, due to their small size, nanoparticles have the potential to transport and disseminate contaminants adsorbed on their surfaces into environmental compartments with greater risk to human, animal, or plant health. This potential consequence of nanoparticle application remains largely unstudied. Here, we studied the application of three adsorbents, including zeolite (Z, micrometric size), nanomagnetite (Mt), and a nanomagnetite-zeolite composite (MtZ) intended to mediate arsenic toxicity in hydroponic tomato cultures. Adsorption studies showed an arsenate adsorption sequence of MtZ (6.2 mg g-1) ≥ Mt (4.7 mg g-1) â‰« Z (0.3 mg g-1). Tomatoes grown under the Mt condition demonstrated the lowest growth rate (4.2 cm), corresponding to a 45% decrease compared to the control (7.6 cm), as well as the highest oxidative stress level (0.024 µmol g-1) as indicated by malondialdehyde (MDA) concentration, almost twice the control (0.014 µg g-1). Tomatoes grown under MtZ conditions showed a 22% decreased growth (5.9 cm) but MDA levels (0.012 µmol g-1) were comparable to the control. Together, these results suggest that Mt at the nanometric size could obstruct channels in the plant and prevent absorption of water and nutrients. Anchoring nanomaterials in larger composites of micrometer size presents a promising alternative that would retain their super-adsorbent properties while avoiding toxicity due to nanometric size.


Assuntos
Arsênico , Lycopersicon esculentum , Poluentes Químicos da Água , Purificação da Água , Zeolitas , Adsorção , Arsênico/análise , Humanos , Concentração de Íons de Hidrogênio , Hidroponia , Cinética , Poluentes Químicos da Água/análise
8.
Sci Total Environ ; 754: 142082, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919317

RESUMO

Extensive evidence of elevated arsenic (As) in the food-chain, mainly rice, wheat and vegetables exists. Nevertheless, the importance of exposure from food towards total As exposure and associated health risks in areas with natural occurring As in drinking water is still often neglected, and accordingly mitigations are largely focused on drinking water only. In this study, the contribution of food over drinking water to overall As exposure was estimated for As exposed populations in Bihar, India. Increased lifetime cancer risk was predicted using probabilistic methods with input parameters based on detailed dietary assessment and estimation of As in drinking water, cooked rice, wheat flour and potato collected from 91 households covering 19 villages. Median total exposure was 0.83 µg/kgBW/day (5th and 95th percentiles were 0.21 and 11.1 µg/kgBW/day) and contribution of food (median = 49%) to overall exposure was almost equal to that from drinking water (median = 51%). More importantly and contrary to previous studies, food was found to contribute more than drinking water to As exposure, even when drinking water As was above the WHO provisional guide value of 10 µg/L. Median and 95th percentile excess lifetime cancer risks from food intake were 1.89 × 10-4 and 7.32 × 10-4 respectively when drinking water As was below 10 µg/L and 4.00 × 10-4 and 1.83 × 10-3 respectively when drinking water As was above 10 µg/L. Our results emphasise the importance of food related exposure in As-endemic areas, and, perhaps surprisingly, particularly in areas with high As concentrations in drinking water - this being partly ascribed to increases in food As due to cooking in high As water. These findings are timely to stress the importance of removing As from the food chain and not just drinking water in endemic areas.


Assuntos
Arsênico , Água Potável , Oryza , Poluentes Químicos da Água , Arsênico/análise , Exposição Ambiental/análise , Farinha , Contaminação de Alimentos/análise , Índia/epidemiologia , Triticum , Poluentes Químicos da Água/efeitos adversos , Poluentes Químicos da Água/análise
9.
Chemosphere ; 262: 128384, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182105

RESUMO

Arsenic (As) polluted food chain has become a serious issue for the growth and development of humans, animals and plants. Nitric oxide (NO) or silicon (Si) may mitigate As toxicity. However, the combined application of NO and Si in mitigating As uptake and phytotoxicity in Brassica juncea is unknown. Hence, the collegial effect of sodium nitroprusside (SNP), a NO donor and Si application on B. juncea growth, gas exchange parameters, antioxidant system and As uptake was examined in a greenhouse experiment. Arsenic toxicity injured cell membrane as signposted by the elevated level of malondialdehyde (MDA) and hydrogen peroxide (H2O2), thus decreasing the growth of stressed plants. Moreover, As stress negatively affected gas exchange parameters and antioxidative system of plants. However, NO or/and Si alleviated As induced oxidative stress through increasing the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), along with thiol and proline synthesis. Furthermore, plants treated with co-application of NO and Si showed improved growth, gas attributes and decreased As uptake under As regimes. The current study highlights that NO and Si synergistically interact to mitigate detrimental effects of As stress through reducing As uptake. Our findings recommend combined NO and Si application in As spiked soils for improvement of plant growth and stress alleviation.


Assuntos
Arsênico/metabolismo , Mostardeira/fisiologia , Óxido Nítrico/química , Silício/química , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Arsênico/toxicidade , Ascorbato Peroxidases/metabolismo , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Mostardeira/metabolismo , Doadores de Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/toxicidade , Superóxido Dismutase/metabolismo
10.
Food Chem ; 336: 127587, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777657

RESUMO

Thermal processing or the digestion process can alter the forms of arsenic (As) present in food. Identification of As species is necessary to accurately determine the risk associated with food consumption. X-ray absorption near-edge structure (XANES) was used to investigate As species in rice, asparagus, and garlic boiled in water containing As(V), and in their bioaccessible fractions (solubilized As after gastrointestinal digestion). The XANES analysis revealed the presence of As(III) (11871.5 eV) or As(III)-S [As(III)-Cys, 11869.6 eV] solution in the cooked foods and in their bioaccessible fractions. The percentage of trivalent species (12-55%) followed the order asparagus ≫ rice ≈ garlic. In the asparagus and garlic samples, part of the As(V) (tetrahedral form) [11875 eV] that had been added appeared in the form of an octahedral As(V) compound [As(V)-glycerol, 11876 eV]. All these changes could considerably modify the risk associated with ingestion of As-contaminated food.


Assuntos
Arsênico/análise , Espectroscopia por Absorção de Raios X/métodos , Asparagus (Planta)/química , Asparagus (Planta)/metabolismo , Culinária , Análise de Alimentos , Alho/química , Alho/metabolismo , Oryza/química , Oryza/metabolismo
11.
Sci Total Environ ; 753: 141962, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32890875

RESUMO

Arsenic (As) is a known human carcinogen with a hitherto unknown mechanism of action. Dimethylarsinic acid (DMAV) is a methylated metabolite of arsenicals found in most mammals, and long-term exposure to DMAV can lead to bladder cancer in rats. Human epidermal growth factor receptor 2 (HER2) is an oncogenic factor that is overexpressed in bladder cancer, but its role in the initiation and progression of As-induced bladder cancer has not been elucidated. We found that HER2 was up-regulated in human uroepithelial cells treated with arsenite as well as in the bladder tissues of DMAV-exposed rats. HER2 overexpression correlated to increased cell proliferation, epithelial-to-mesenchymal transition (EMT), migration and angiogenesis in vitro. The anti-HER2 monoclonal antibody trastuzumab significantly decreased serum vascular endothelial-derived growth factor (VEGF) levels and that of proliferation-related proteins in the bladder tissues of DMAV-exposed rats. Furthermore, inhibition of HER2, as well as that of the MAPK, AKT and STAT3 pathways, attenuated arsenite-induced proliferation, migration and angiogenesis of human uroepithelial cells, and increased apoptosis rates in vitro. These findings indicate that HER2 mediates the oncogenic effects of As on bladder epithelial cells by activating the MAPK, PI3K/AKT and Src/STAT3 signaling pathways, and is therefore a promising biomarker.


Assuntos
Arsênico , Animais , Arsênico/toxicidade , Proliferação de Células , Células Epiteliais , Humanos , Fosfatidilinositol 3-Quinases , Ratos , Receptor ErbB-2 , Transdução de Sinais
12.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 36(10): 871-876, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33148380

RESUMO

Objective To investigate the effects of inorganic arsenic exposure on the differentiation of renal CD4+T lymphocytes and the possible mechanism. Methods Female C57BL/6 mice were randomly divided into control group, (2.5, 5, 10) mg/kg NaAsO2 exposure groups, 10 mice in each group. As was administered once intragastrically for 24 hours, and control mice were treated with normal saline. Real-time fluorescence quantitative PCR was used to detect T helper type 1 (Th1) cell-specific transcription factor T-box expressed in T cells (T-bet) and IFN-γ, Th2 cell-specific transcription factor GATA-binding protein 3 (GATA3) and interleukin 4 (IL-4), Th17 cell-specific transcription factor retinoic acid related orphan nuclear receptor γt (ROR-γt) and cytokine IL-22, regulatory T cells (Tregs)-specific transcription factor forkhead box P3 (FOXP3) and cytokine transforming growth factor-ß (TGF-ß) mRNA levels. We used commercial kits to detect catalase (CAT) activity and total antioxidant capacity (T-AOC) in serum as well as renal malondialdehyde (MDA) and superoxide dismutase (SOD). Results Compared with the control group, the body mass, renal mass and kidney index of the mice in all arsenic-treated groups have no significant changes. The levels of the master transcription factors T-bet, GATA3, ROR-γt and FOXP3 as well as related cytokines IFN-γ, IL-4, IL-22 and TGF-ß of Th1, Th2, Th17 cells and Tregs decreased in the arsenic-treated groups. Serum CAT activity and T-AOC level in the arsenic-treated mice dropped greatly. In addition, arsenic markedly increased renal MDA level while decreased SOD activity. Conclusion Inorganic arsenic exposure can suppress renal T cell subpopulation function and induce renal oxidative injure.


Assuntos
Arsênico/toxicidade , Rim/efeitos dos fármacos , Estresse Oxidativo , Linfócitos T Reguladores/efeitos dos fármacos , Células Th1/efeitos dos fármacos , Células Th2/efeitos dos fármacos , Animais , Citocinas/metabolismo , Feminino , Fatores de Transcrição Forkhead/metabolismo , Fator de Transcrição GATA3/metabolismo , Rim/imunologia , Camundongos , Camundongos Endogâmicos C57BL
13.
Environ Monit Assess ; 192(12): 785, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33241452

RESUMO

The experiment was conducted to assess the impact of arsenic (As)-contaminated groundwater irrigation on soil health and crop quality. Geo-referenced groundwater, soil, and crop produce samples were collected from the middle Gangetic plains of Maner block of Patna and were analyzed for As content. The result showed that long-term application of As-contaminated groundwater (0.017 to 0.677 mg L-1) buildup significant amount of As in the soil (0.41 to 8.66 mg kg-1). A significant correlation (r2 = 0.922) was also observed between As content in groundwater and the soil. The content of As in groundwater also affected crop quality and accumulated metal content in different crop parts. Total As content in crop samples ranged from 0.010 to 0.963 µg g-1 of dry weight. The average As content in crop followed order: oilseeds > cereals > vegetables > pulses. Therefore, produce quality should be monitored frequently for As uptake as there is a great chance of As accumulation in food crops. Hence, these approaches are useful for the formulation of policy guidelines for the management of As-containing groundwater and routine risk assessment of As-contaminated soils.


Assuntos
Arsênico , Água Subterrânea , Poluentes do Solo , Arsênico/análise , Monitoramento Ambiental , Cadeia Alimentar , Contaminação de Alimentos/análise , Solo , Poluentes do Solo/análise
14.
An Acad Bras Cienc ; 92(3): e20200974, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33175018

RESUMO

The use of industrial waste as an additive in soil improvement has many advantages, including recycling of waste, reducing the need for waste storage, and obtaining an economical material. With the use of these wastes, desired positive results are obtained in some geotechnical properties of soil. However, the wastes can create trace element contamination in soil and groundwater. In this study, trace elements originating from industrial wastes contaminating groundwater are investigated. The industrial wastes were mixed at different proportions with the soil. These mixtures were compacted into a permeameter cells, and a seepage tests were performed. The leachates obtained from seepage tests were analyzed with inductively coupled plasma mass spectrometry (ICP-MS) to determine trace elements. The measured trace element quantities were compared with the allowable values in the relevant standards (EPA 822, WHO, TS266). The results reveal that quantitative values of the trace elements from the leachates were within the allowable limits, except for arsenic and chromium. Furthermore, when fly ash is used As and Cr can be combined with ettringite and be immobilized. Boron and silica fume are hazardous substances caused by trace elements. However, considering its long-term effect, they can be used with fly ash.


Assuntos
Arsênico , Oligoelementos , Arsênico/análise , Cinza de Carvão/análise , Resíduos Industriais/análise , Solo , Oligoelementos/análise
15.
Huan Jing Ke Xue ; 41(9): 4322-4332, 2020 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124314

RESUMO

Immobilization of bacteria on biochar can improve the performance of the soil complex polluted with cadmium (Cd) and arsenic (As). In this study, bacteria (Delftia sp. B9, B9), biochar (corn stalks biochar, CSB), and biochar-bacteria complexes (B-CSB) were used as adsorption materials to explore the adsorption characteristics of Cd and As. The effects of pH on the adsorption performance of Cd and As and the ion removal from the aqueous solution were investigated, and the adsorption behaviors were simulated using an isothermal adsorption model. The changes in Cd and As speciation with the addition of B9, CSB, and B-CSB to As and Cd-contaminated soil were explored. The results showed that the Cd-saturated adsorption capacities of B9, CSB, and B-CSB were 49.43, 82.68, and 75.38 mg ·g-1, respectively; the As-saturated adsorption capacities were 24.67, 42.92, and 34.03 mg ·g-1, respectively. The concentration of available Cd and As significantly decreased, whereas the residual fraction increased after the addition of B-CSB. B-CSB was shown to be an effective material for the remediation of soil complexes polluted with Cd and As.


Assuntos
Arsênico , Poluentes do Solo , Adsorção , Cádmio , Carvão Vegetal , Solo , Poluentes do Solo/análise , Zea mays
16.
Water Res ; 185: 116257, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33086466

RESUMO

This study identifies causes of rising arsenic (As) concentrations over 17 years in an inter-montane aquifer system located just north of the Trans-Mexican-Volcanic-Belt in the Mesa central physiographic region that is extensively developed by long-screened production wells. Arsenic concentrations increased by more than 10 µg/L in 14% (3/22) of re-sampled wells. Similarly, in a larger scale analysis wherein As concentrations measured in 137 wells in 2016 were compared to interpolated, baseline concentrations from 246 wells in 1999, As concentrations rose more than 10 µg/L in 30% of wells. Between 1999 and 2016, the percentage of all wells sampled in each basin-wide sampling campaign exceeding the World Health Organization's 10 µg/L drinking water limit increased from 38 to 64%. Principal Components Analysis (PCA), step-wise multiple regression, and Random Forest modeling (RF) revealed that high As concentrations are closely associated with high pH and temperature, and high concentrations of fluoride (F), molybdenum (Mo), lithium (Li), sodium (Na) and silica (Si), but low calcium (Ca) and nitrate (NO3) concentrations. Pumping-induced mixing with hot, geothermally impacted groundwater generates alkaline water through hydrolysis of silicate minerals. The rising pH converts oxyanion sorption sites from positive to negative releasing As (and Mo) to pore waters. The negative correlation between nitrate and As concentrations can be explained by conservative mixing of shallow, young groundwater with geothermally influenced groundwater. Therefore water carrying an anthropogenic contaminant dilutes water carrying geogenic contaminants. This process is enabled by long well screens. Over-exploitation of aquifers in geothermal regions for agriculture can drive As concentrations in water from production wells to toxic levels even as the total dissolved solids remain low.


Assuntos
Arsênico , Água Subterrânea , Poluentes Químicos da Água , Arsênico/análise , Monitoramento Ambiental , México , Poluentes Químicos da Água/análise
17.
Chemosphere ; 261: 128160, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113648

RESUMO

Up to now, complicated organoarsenicals were mainly identified in marine organisms, suggesting that these organisms play a critical role in arsenic biogeochemical cycling because of low phosphate and relatively high arsenic concentration in the marine environment. However, the response of marine macroalgae to inorganic arsenic remains unknown. In this study, Pyropia haitanensis were exposed to arsenate [As(V)] (0.1, 1, 10, 100 µM) or arsenite [As(III)] (0.1, 1, 10 µM) under laboratory conditions for 3 d. The species of water-soluble arsenic, the total concentration of lipid-soluble and cell residue arsenic of the algae cells was analyzed. As(V) was mainly transformed into oxo-arsenosugar-phosphate, with other arsenic compounds such as monomethylated, As(III), demethylated arsenic and oxo-arsenosugar-glycerol being likely the intermediates of arsenosugar synthesis. When high concentration of As(III) was toxic to P. haitanensis, As(III) entered into the cells and was transformed into less toxic organoarsenicals and As(V). Transcriptome results showed genes involved in DNA replication, mismatch repair, base excision repair, and nucleotide excision repair were up-regulated in the algae cells exposed to 10 µM As(V), and multiple genes involved in glutathione metabolism and photosynthetic were up-regulated by 1 µM As(III). A large number of ABC transporters were down-regulated by As(V) while ten genes related to ABC transporters were up-regulated by As(III), indicating that ABC transporters were involved in transporting As(III) to vacuoles in algae cells. These results indicated that P. haitanensis detoxifies inorganic arsenic via transforming them into organoarsenicals and enhancing the isolation of highly toxic As(III) in vacuoles.


Assuntos
Arsênico/toxicidade , Rodófitas/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Arseniatos/química , Arseniatos/toxicidade , Arsênico/química , Arsenitos/química , Arsenitos/toxicidade , Cromatografia Líquida de Alta Pressão , Ecotoxicologia , Regulação da Expressão Gênica/efeitos dos fármacos , Espectrometria de Massas , Monossacarídeos/química , Rodófitas/genética , Rodófitas/metabolismo , Alga Marinha/efeitos dos fármacos , Poluentes Químicos da Água/química
18.
J Environ Qual ; 49(2): 417-427, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33016420

RESUMO

Isotopically exchangeable metals in soil, also termed labile metals, are reversibly bound to soil surface and are a better index of the environmental risk of the metals than are their total concentrations. In this study, labile fractions of potentially toxic elements were surveyed in metal mining-impacted soils of Mexico to test the relative importance of soil properties (pH, effective cation exchange capacity, organic matter, etc.) or attributes of the mines (ore type and lithology, metal mineralogy, etc.) on the fractions of labile elements. Mining waste-impacted soils, corresponding uncontaminated soils and mining waste were collected around 11 metal mines in Mexico presenting contrasting ore types. Pseudo-total concentrations and labile fractions of Cd, Ni, Zn, Pb, Cu, and As were determined by aqua regia digestion and isotope dilution, respectively. Pseudo-total concentrations of these elements ranked: waste > contaminated soil > uncontaminated soils, and Zn and As dominated the concentrations of toxic elements. The labile fractions (% of total) in the soils ranked, with median values in brackets, Pb (22) > Cd (18) > Cu(15) > Ni∼Zn(13) > As(9). The labile fractions of waste samples were slightly higher than those of soil samples suggesting either a high weathering of mining wastes or the stabilization of heavy metals by soil. Stepwise multiple regression showed that soil properties rather than source attributes primarily explained the %E of most elements, except for Zn and As for which the ore lithology was the dominant factor. This study showed that earlier generic models explain metal lability adequately in mining waste-impacted soils.


Assuntos
Arsênico , Poluentes do Solo/análise , Monitoramento Ambiental , México , Solo
19.
Environ Monit Assess ; 192(11): 712, 2020 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-33070268

RESUMO

A major public health concern in Mexico is the natural contamination of groundwater with fluoride and arsenic. Therefore, this work aimed to evaluate the magnitude of human health risk after determining fluoride and arsenic concentrations in groundwater samples (n = 50) from the Metropolitan area of the city of San Luis Potosi, Mexico. Fluoride levels in water were determined via a potentiometric method using an ion-selective electrode. Arsenic concentrations in water samples were determined with an Atomic Absorption technique. Subsequently, a probabilistic health risk assessment was developed (Monte Carlo Analysis). Fluoride levels in water ranged from 0.20 to 3.50 mg/L. For arsenic, the mean level found in the assessed water samples was 15.5 ± 5.50 µg/L (range: 2.50-30.0 µg/L). In addition, when the probabilistic health risk assessment was completed, a mean HI (cumulative hazardous index) of higher than 1 was detected, indicating a high NCR (non-carcinogenic risk) for children and adults. According to the results found in this study, exposure protection campaigns are imperative in the Metropolitan area of the city of San Luis Potosí, Mexico, to successfully diminish exposure to arsenic and fluoride and, as a consequence, decrease the NCR in the population living in that region of Mexico.


Assuntos
Arsênico , Água Potável , Adulto , Arsênico/análise , Criança , Cidades , Água Potável/análise , Monitoramento Ambiental , Fluoretos/análise , Humanos , México , Medição de Risco
20.
Vet Clin North Am Food Anim Pract ; 36(3): 581-620, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32948413

RESUMO

Water is the most important nutrient for rangeland livestock. However, competition with municipalities, industry, and other water users often results in grazing livestock being forced to use water supplies that are less than perfect. Surface water in western rangleands are often contaminated by mineral extraction, irrigation runoff and other human activities. Mineral contaminants in drinking water are additive with similar contaminants in feedstuffs. The goal of this article is to provide producers and veterinarians with the basic background to make informed decisions about whether a given water supply is "safe" for livestock.


Assuntos
Doenças dos Bovinos/induzido quimicamente , Doenças dos Bovinos/prevenção & controle , Metais/análise , Metais/envenenamento , Qualidade da Água , Água/normas , Animais , Arsênico/análise , Intoxicação por Arsênico/prevenção & controle , Intoxicação por Arsênico/veterinária , Bovinos , Intoxicação por Flúor/prevenção & controle , Intoxicação por Flúor/veterinária , Fluoretos/análise , Humanos , Água/análise , Abastecimento de Água/normas
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